Release link



Oct. 16, 1945'.

D. w. coo'PER RELEASE LINK Filed March 20, 1944 2 Sheets-Sheet l 022ml. W 600,027

A /7zrentar After 722 Oct. 16, 1945.

D.' W. COOPER 2,386,932

' RELEASE LINK Filed March 20, 1944 2- Sheets-Sheet 2 Oanz'cl W Cqoper 113 1 is provided with a t ming de ice Patented Oct. 16, 1945 RELEASE el um y oo Waltham Chase E land, assignor to Cunlifie-Gwen Aircraft, Limited, Swaythling, near Southampton, England, a British joint-stock company Application March 20, 1944, Serial No. 527,365 In Great Britain February 22, 1943 12 Claims.

This invention relates to releaseelinks for parachute-borne loads to be dropped from aircraft.

The invention has for its main object to provide an improved release-link of this character which operates automatically to disconnect the load from its parachute or parachutes when the said load reaches the ground or other support.

Another object of the invention is to provide an improved release-link controlled by a timing device so as to prevent premature release within a predetermined period after the dropping of the load from the aircraft.

More specifically, the invention has for an object to provide an automatic release-link comprising parts co-.-.operating in the manner of key and keyhole members and partially rotatable in relation to one another, the parts when rotated interengaging under tension due to the load, with spring means tending to reverse the relative rotation as soon as the load tension is removed.

[A further object is to provide an automatic release link comprising relatively rotatable parts, interengaging under the load-tension, with means for holding the parts in their relatively rotated position under the control of a timing device which withdraws the holding means from their operative position at the expiration of a predetermined period.

A still further object is to provide a delayaction release link having a timing device operated by the actual load-tension upon the link.

Other objects and advantages of theinvention will hereinafter appear from the following description of a preferred embodiment, given with reference to the accompanying drawings, in which: I h

Fig. 1 is a part sectional elevation of the-improved release-link, in the enga ed and locked position.

Fig. 2 is a sectional elevation viewed at right angles to Fig. 1, the link being in the released position; the co=operating member is shown separately in Fig. 3. a

Fig. 4 is a cross section of the link on the broken line 41-401 Fig. 1, but showing the parts not yet turned to engaged osition,

i s. and l ar a onal e evation of three separate parts of. the internal mecha- .nism o e l n Fi s- 6, 8 nd 9 being the co respending plan views.

Fig. 11 is ,a cross-section of thelink on the broken line 4-4 of Fig. 1, showing the parts in t e en aged nositi.

: n th constru tion i lustrated th rel a eof a dashpot constituted by a hydraulic cylinder 1,! conta n a p s n 1 he c inde in connec ed to e oa d th pis n e n o nected through the .coeoperating 'keypiece and keyhole member to the loadesupporting para.- chute. The hydraulic cylinder is composed of two parts ll, Lia, each having a closed end; the two parts are detachably connected to oiher b a screwed joint it. Two diametrically Opposite sl ts 1.4 are formed longitudinally along the cylinder throu which a pair of e dg oh p ns 5 are fitted into the piston; the projecting heads of the .g dgeon pins engage in a pair of holes It a socket member ll which is .slidable on the xt rior of th c lind r, the .gu e n pins be retained by an encirclin spring clip 18 and the lid n mov m nt being l m t b he le h o the slots 14 in which the glidgeon pins are ena d- The end of th o k t member mo from the gndgeon pins is provided with an int n l an e l 9 o fia annu f m hav n w diametrically opposite notches .29; the Parts of the fla e left be we n t ese otches on ti ut a pair or Jaw t e n tc ed flange a t a keyhole member. The adjacent end of the .cylinderhas a projecting sleeve of smaller diameter, s o ted lon tudinall o eav wo oppo i ton or W lls .21 of arc a e s ape ch proximately degrees in angular extent, which a ad d to oach h no ch s 2.0 e w en the jaws in the flanged end .of the socket member I? when the latter is slid over the cylinder but to be moyedaway from the notches when the socket memberslides away from the cylinder to the limit o it tra e n e h c t ol o the imi g device.

The socket member I] is also provided internally andat a position clear of the movement of the cylinder, with an inserted ring ,22 (shown separately in Fig. .5 and 6) having a st ppe wanes d a rically po t extremities of which are secur d by rivets 24 e ga ed h ugh the flange I of he socket member; the inner edge .of this walled ring is rebated to produce a qaadrantal-section recess .25 supporting ,a rotatable sleeve .25 .(show-n separately in Figs. 7 and ,8) which extends almost as far as the-notched flange I9. The end of the sleeve adjacent .to the notched flange is slotted lo gitud na l t f m two diame ri ll opp site notches Z'l capable of registering approximately with thenotches 2.0 in theflange' l9 and with the tongues 21, as shown in Fig. 2; by rota- ..tion .of the sleeve 26, these notches ,2] can he brought partly into register with .the jaws of the of the socket member; this ring is notched at 32 in register with the notches 20 of the flange and it is supported by the stepped wall 23 of the ring 22, the highest portions of the wall extending upwards through the notches 32 and into the notches 20, where they are secured by the rivets 24. The lower face of this ring 3| is provided with two shallow radial grooves 33, located for. example at angles of about 68 degrees from the notches 32; 1

the edges of the grooves 33 are bevelled at angles of 45 degrees.

The keypiece consists of a block or butterfly 34,[having two opposite wings 35, rotatably mounted upon a spigot member 36 adapted to enter the central hole in the flange IQ of the socket member; the spigot 35 and the boss of 'the keypiece block 34 fit loosely between the opposite concave faces of the jaws while the keypiece wings 35 are slidable through the notches 20 between the jaws; the angular extent or width through the notches 2!! (as seen on the right hand side of Fig. 4) and also enter with some clearance into the notches 21 (as seen on the left hand side of Fig. 4), engagement of the parts being then able angle and against the action of the spring 28 so as to bring the keypiece wings 35 behind the jaws or solid portions between the notches 20 of the keyhole member (as seen in Figs. 1 and 11). In this engaged position, the gaps between the keypiece wings will register with the notches 20 of the flanged keyhole member, and the parts can therefore be locked against reverse rotation bycocking or setting the timing device, thereby bringing the tongues or arcuate walls 2| constantly registering with the notches 20 into the gaps between the wings (as seen in Fig. 11') so as to obstruct the return of the keypiece. At the expiration of the predetermined period, which will be made sufiiciently long to ensure that the. pull on the link has settled down to a steady value after the deployment of the parachute or parachutes, the timing device will withdraw its tongues or arcuate walls 2| from the registering of the wings is such that they can slip freely effected by turning the keypiece through a suitgaps and notches, so that the wings and jaws are held in engagement by the pull upon thelink. As soon as this pull is removed or reduced by the load reaching the ground or other surfaceythe spring 28 will rotate the keypiece back to its initial angular position (as seen in Fig. 4) so that the wings can slip through the notches of the keyhole member, thereby disconnecting the link and releasing the load from the parachute before any damage or inconvenience can be caused by the load being dragged along the ground or other surface on which it has alighted.

The keypiece is conveniently mounted upon the spigot 36 by means of a headed screw or bolt 31 engaged in a screw-threaded hole 38 in the axis of the spigot; in order to prevent thetransmis- 'sion of any twist from the load to the parachute "connections; or vice versa, the keypiece 34 is made freely rotatable upon a bush 39 clamped on the screw shank between the head of the screw and the adjacent end of the spigot, a locking 'pin' 49 being passed diametrically through the spigot and screw to fix the latter. The other end of the spigot, which carries a flat flange 4| covering the notched flange of the socket member, is extended to form a boss 42 for the mounting of a shackle 43 to which the parachute connectionsare attached, the shackle being secured by a transverse bolt or pin 44.

Suitable coupling means are provided for turn- -ing the keypiece or butterfly 34 against the action of the coiled spring 28 after the said keypiece has been passed through the keyhole Tormed by the notched flange I9 and its wings 35 have been engaged in the notches 21 of the rotatablesleeve; for-this purpose, the upper surface of the keypiece is shown with a mortise 45 extending diametrically across it at right angles to the center line-of the wings 35, and the lower surface of the spigot member 36 is cut away on two opposite sides, as indicated at 45, to leave a tenon 41 adapted to engage in the mortise 45 when the 'parts 34, 36 are brought together by relative movement along the bush-fitted screw 31. Thus, the keypiece can be turned manually by means of the shackle 43, after the wings 35 have been engaged in the notches 21 of the rotatable sleeve within the body of the link; the extent of the turning movement required to engage the wings 35 beneath the jaws of the notched flange I!) may be up to 90 degrees, but in the example illustrated the angular movement for engagement and for subsequent release has been selected as 68 degrees, corresponding to the angular location of the radial grooves 33 upon the latching ring 3|.

The keypiece 34 is also provided with two radial ribs 48 of small height, upstanding from the wings 35 and aligned therewith; these ribs, which come into register with the radialgrooves 33 of the latching ring after the keypiece has been turned through the angular movement of 68 degrees mentioned, are of the same width as the said grooves and have correspondingly bevelled edges. Consequently, when the keypiece has been coupled rotationally to the spigot 36 and its shackle 43 by the mortise and tenon device, the 'keypiece can be engaged with the socket H by pushing its wings 34 through the notches 20 of the socket flange into the notches 21' of the rotatable sleeve, and then turning it approximately '68 degrees against the action of the torsion spring 28, so as to bring its wings 35 beneath the jaws of-the socket flange, the ribs 48 then entering the grooves 33 of the latching ring. While the parts are in this position, the hydraulic cylinder is forced up into the socket so as to engage its tongues 2| in the gaps between the wings 35 '(as seen in Fig. 11), thereby locking the keypiece against reverse'rotation until the piston |2 of the timing device completes its return stroke. When that occurs, the wings and jaws will be held in engagement by the pull due to the load,

the operation of the latching ring 3| being suifl- "cient to resist the torque produced by the spring 28; as soon as the load reaches the ground, however, the pull upon the link will be relieved so that the latching ring will no longer hold the keypiece against the action of the spring, but the rotatable sleeve 26 will be caused to turn the -wings 35 of the keypiece into register with the notches 20 of the flange, as seen in Fig. 4, thereby allowing the keypiece to disengage from the socket ll, as indicated in Fig. 3, under the upward "pull of the parachute.

The timed Withdrawal of the locking tongues 2| from the position obstructing the Wings 35 of the keypiece takes place before the load reaches the lower shackle fifl; The veffect of these-opposing forces will be to draw down the cylinder 1],: thus driving the liquid from above the piston: 12 throughl -theirestricted passage in. the middle'iof the annular valve 56 to below theipiston; due to theiresistance caused by the restricted'passage for the liquid; the descent of the cylinder H will be.-de1ayed untilall'jerking of the shackle con nections has ceasedso thatthe load is supported steadily by the parachute or parachutes. By this time, the cylinder will have withdrawn the locking tongues 21 down to the level seen in Fig. 2, leaving the keypiece unlocked but held firmly in contact with the latching ring '31 by the tension acting through the link; the engagement of the ribs 48 within the grooves33 of the latching ring will sufiice=j to prevent thelspring 28 from rotating the sleeve 26 andkeypiece 34, so long asthe load tension continues to act.

So soon, however, as the load reaches the ground-or other support, the tension upon the link will diminish; consequently, the spring 28 will be able to rotate the sleeve 26 and keypiece 34 back to the unlocked position seen in Fig. 4, the keypiece being pulled out through the notched flange 19 by the drift of the parachute or parachutes, while the body of the link andthe load connected to the shackle to will remain upon the ground. 1 I

What I claim is: 1 l

l. Arelease-link, comprising a body member and a keypiece, said body member having a noncircular keyhole for reception of said. keypiece, said body member and keypiece being relatively rotatable for interengagement after insertion of said keypiece into said keyhole, means for holding said keypiece and body member relatively rotated to interengagement position, means for applying load-tension to said body member and keypiece, said load-tension acting to maintain the interengagement of said body member and keypiece, and spring means adapted to cause reverse relative rotation of said keypiece and body member upon removal of the load-tension from said applying means, said applying means including a timing device operated by the load-tension and controlling said holding means.

2. A release-link comprising a body member and'a'k'eypiece, said body member having a noncircular keyhole for insertion of said keypiece,

said body member and keypiece being relatively rotatable for interengagementafter insertion of said keypiece into said keyhole, means slidable parallel to the axis of relative rotation of said body member and keypiece for holding them relatively rotated to interengagement position, means for applying load-tension to said body member and keypiece, said load-tension acting to maintain the interengagement of said body member and keypiece, and spring means adapted to cause reverse relative rotation of said keypiece and body member upon removal of the load-tension from said applying means, said applying means including a'timing device controlling said slidable holdin means, and said timingdevice coming into operation at the application of load tension to said body member and keypiece.

' 3. A release-link comprising a body member having an interrupted flange, a winged keypiece engageable with said body member and rotatable in relation thereto, means for holding. said keypiece and body member in relatively rotated position, means for applying load-tension to said body member-and keypiece, said load-tension acting tomaintainthe engagement or ai bgdy mined period,- and said keypiece being then disenload-tension is relieved, l

4-. A release-linkcomprising a socketand a keypiece, said socket having anon-circular keyhole forinsertion of said keypiece, said socket nd ke pie e e n re a ve y ota ble o inter engagement alter insertion of said keypiece into said keyhole, a;member rotatable within said socket, saidmember being adapted for engagement ofsaid keypiece when inserted. into said keyhole and being rotatable therewithin relation to said socket, a sprin Opposing the rotation of said member in relation to said socket, means for holding said keypiece and socket in the relatively rotated position, and-means for apply n loadtension to said socket and keypiece, said load ten sion' acting to maintain the interengagementof said socket and keypiece in the relatively, rotated position, and saidapplying; means including a timingdevice controlling said holding means. 5. A release-link comprising a bodymember anda winged keypiece said body member hay ing an internal flange notched to iorina keyhole for insertion of said keypiece, said body member andkeypiece being relatively rotatable after insertion or" said keypiece into, saidkeyhole, said keypiece then having its wings engaged withinter notch portions of the flange of said body member, ,means ,for holding said keypiece and .jbody member relatively rotated, means for applying; load-tension to said keypiece and body niember,, said load-tension acting to maintain theengagement'ofsaid body member and keypiece in the relatively rotated position, and spring means adapted to cause reverse relative rotation of said keypiece and body member upon removal of load-tension from .said "applying means, said applying means including a timing device ior controlling said holding means. i

6. A release-link comprising a socket having an internalfiange notched toiorm a keyhole, a

gageable from saidbody member assoon as'the keypiece for insertion inth'e keyhole of said sockwith "the portions of said flange between the notches thereof, a sleeverotatable within said fs'ocket, said sleeve having notches adapted for "engagement by the wingsiof said keypiece m teister with the notchescf saidflange, a, spring controlling the rotation of saidsleeve, means for holding said. keypiece' and socket in relatively rotated position, a, timing device controllin said holding means, and means for applying load tension through said timing device to said socket and keypiece, said' load tension'aeting tomai'ntain the engagement of said socket and keypiece 'in the relatively rotated position, and said timing device delaying the reverse relative rotation of said keypiece and socket by said spring-controlled sleeve for-a predetermined-period after the'application of keypiece. V

"7.- A release-link comprising a body member .anda keypiece, said body member having a keythe load-tension to said socket and hole for insertion of said keypiece, said body member and keypiece being relatively rotatable for interengagement after insertion of said keypiece into said keyhole, means for applying loadtension to said body member and keypiece, said load-tension acting to maintain the engagement of said body member and keypiece in the relatively rotated position, a swivelling connection insaid applying means, spring means adapted to cause reverse relative rotation of said keypiece and body member upon removal of load-tension from said applying means, and means for holding said keypiece and body member relatively rotated, said applying means including a timing device for controlling said holding means.

8. A release-link comprising a socket having an internal annular flange notched at opposite points, a keypiece for engagement with said flange, said keypiece having opposite wings adapted to pass through the notches of said flange, said keypiece and socket being thereafter relatively rotatable for bringing said wings into registering engagement with portions of said flange between the notches thereof, means for applyin load-tension to said socket and keypiece, said load-tension acting to maintain the engagement of said socket and keypiece in the relatively rotated position, spring means adapted to cause reverse relative rotation of said keypiece and socket upon removal of load tension from said applying means, said applying means including a timing device enclosed in said socket, and means for holding said keypiece and socket in relatively rotated position, said holding means bein controlled by said timing device.

9. A release-link comprising a socket having an internal annular flange notched at opposite points, a keypiece for engagement with said flange, said keypiece having opposite wings adapted to pass through the notches of said flange, said keypiece and socket being thereafter relatively rotatable for bringing said wings into registering engagement with portions of said flange between the notches thereof, means for holding said keypiece and socket in relatively rotated position, a timing device enclosed in said socket, said holding means being controlled by said timing device, means for applying load-tension to said keypiece and timing device, the load-tension applied to said timing device being transmitted to said socket so as to maintain the engagement of said keypiece and socket in the relatively rotated position, and spring means adapted to cause reverse relative rotation of said keypiece and socket upon removal of load-tension from said applying means.

10. A release-link comprising two members rotatable in relation to one another for co-operative engagement under axial tension due to the load, the relative rotation taking place about an axis in alignment with the load tension, means for holding said members in relatively rotated position, spring means adapted to cause reverse relative rotation of said members about said axis upon removal of the load-tension, and a timing device operated by the load-tension for withdrawing said holding means after a predetermined period, said members being then disengageable as soon as the load-tension is relieved.

11. A release-link comprising a socket and a keypiece, said socket having a non-circular keyhole for insertion of said keypiece, said socket and keypiece being relatively rotatable for interengagement after insertion of said keypiece into said keyhole, a member rotatable within said socket, said member bein adapted for engagement by said keypiece when inserted into said keyhole and being rotatable therewith in relation to said socket, a spring opposing the rotation of said member in relation to said socket, means for latching said keypiece and socket in the relatively rotated position, and means for applying load-tension to said socket and keypiece, said load-tension acting to maintain the interengagement of said socket and keypiece in the relatively rotated position and also to maintain said keypiece in engagement with said latching means.

12. A release-link comprising a socket and a keypiece, said socket having a non-circular keyhole for insertion of said keypiece, said socket and keypiece being relatively rotatable for interengagement after insertion of said keypiece into said keyhole, a member rotatable within said socket, said member being adapted for engagement by said keypiece when inserted into said keyhole and bein rotatable therewith in relation to said socket, a spring opposing the rotation of said member in relation to said socket, a latching ring secured Within said socket, co-operating ribs and grooves upon said keypiece and latching ring, and means for applying load-tension to said socket and keypiece, said load-tension acting to maintain the interengagement of said socket and keypiece in the relatively rotated position and to maintain said ribs and grooves in engagement in said position.

DANIEL WAUMSLEY COOPER; 

